1. Field of the Invention
The present invention relates generally to a cleaning system for equipment which handles a flow of particulate or powder products. More particularly, the subject invention pertains to a cleaning system as described for a pouch filling system which dispenses dry particulate or powder products, with relatively frequent changeovers between different types of powder products, each of which requires a thorough cleaning of old product from the system.
2. Discussion of the Prior Art
The current prior art pouch filling system contains multiple locations where powder products consistently accumulate or are trapped, particularly in the areas of the cross augers and filler hoppers. Also, many of the seals in the system are worn, damaged or inadequately designed for sealing powder products, which results in more trapping of powder products, leakage in some areas, and extensive cleaning efforts by all operators.
A wet wash is performed periodically on the system to provide a thorough cleaning thereof. This involves removing key internal components, such as augers and seals, and gaining access to all areas of the system by removing sections such as rubber socks and cover plates. All removed components are washed by hand, and all components not removed are washed using a hot water hose or hand-held wipers. All water sprayed into the piping is collected by wet hoses which are clamped to the exit chute of the cross augers, and wet buckets, which are later dumped into a drain.
Numerous problems are associated with wet washes that must be performed on this system.
The amount of water used and the quality of the cleaning job in every case is entirely dependent upon the particular operator performing the task, so a thorough cleaning cannot always be guaranteed and water wastage is possible.
Many of the locations where powder products are trapped are hidden (e.g. beside the chute connecting the diverter to the top of the filler hopper) or difficult to reach (e.g. the far end of the cross auger tubes). This means that some areas become encrusted with powder that has come into contact with water, but was not washed out of the system. Cleaning those areas now requires the use of a scraper, which can result in damage to components and thus further cleaning and flow characteristic problems.
Also, water leakage occurs through some of the seals in the system in areas above the actual pouch filling area, and thus some external parts of the filler system also become wet during a wet wash.
To summarize, many areas of this system needed significant improvements to speed up the cleaning process and reduce the amount of product that enters the effluent stream, such as completely sealing the filling system and eliminating product accumulation areas.
Clean In Place (CIP) systems are known in the prior art, involve somewhat standardized technology, and are used almost exclusively to clean systems handling liquid based products. A large variety of different clean in place systems in the prior art were evaluated in the development of the present invention, and most of these systems are designed with equipment consisting primarily of tanks, liquid pumps, and piping of less than three inches in diameter. In these systems, cleaning is accomplished by the pressurized flow of steam, water and solvents. Therefore, much of this standardized technology does not apply to equipment for handling particulate or powder products. Several clean in place systems were evaluated which were almost identical to the pouch filling system for which the present clean in place system was developed. In particular, a grated parmesan dispensing line and a dinner cheese mix dispensing line were evaluated. However, unlike the system for which the present clean in place system was developed, those systems run only two or three different products over long periods of time, with very infrequent changeovers. Therefore, changeover downtime is not a large concern, and during cleaning, the systems are completely dismantled and washed.
Dry cleans and sugar flushes have also been utilized in the prior art to clean pouch filling systems. A sugar flush involves running sugar through the pouch filling system to allow the sugar to flush and clean the internal components thereof. Dry cleans represent a medium between sugar flushes and full wet washes, because a sugar flush is conducted but some parts are cleaned by hand as well. A dry clean is substantially identical to a sugar flush except that two additional steps are required:
1. All filling funnels and duck bills are blown clean with compressed air.
2. The filler augers and filler hoppers are dropped down so that the components inside the filler hoppers can be sprayed with compressed air. The cleaned augers and hoppers are then replaced.
Added time is also required to blow clean the duck bills and funnels. However, in general blowing of any parts of the filler system should be avoided because of the product dust that results, causing cleaning difficulties for all lines in the area. The necessity of spraying the filler hoppers creates identical problems.